Mushroom farming comprises generally six steps: (1) Phase I composting; (2) Phase II composting; (3) spawning; or (2a/3a) Phase III composting; (4) casing; (5) pinning; and (6) cropping. The most used and least expensive mushroom compost is straw-bedded horse manure to which nitrogen supplements and a conditioning agent, such as gypsum, are added. After the compost ingredients have been mixed, watered and aerated in Phase I for a requisite number of days, the compost is pasteurized in Phase II. Pasteurization kills insects, unwanted fungi or other pests that may be present in the compost.
In a mushroom growing operation using the shelf system, mushrooms are grown in shelves which are about 65 inches wide and about 60 feet long. These shelves are usually stacked in a superimposed position, six or so in a tier, in adjacent tiers that are about 12 feet high. The vertical distance between the superimposed shelves is about 24 inches. In mushroom growing houses, two to four of the tiers may be placed in a single growing room. The aisles between adjacent tiers are generally about 32 inches wide. The head room from the top of the top shelf to the ceiling is also usually limited to about 3 feet. At the front and rear of each tier, only about 3 feet of space is left between the shelf and the respective wall of the mushroom growing house. To complicate material handling, the only access into the growing rooms usually is a door which is about 32 inches wide and only about 6 feet high. There is very limited room for machinery and attendant personnel to maneuver between tiers and into individual shelves.
In the cultivation of mushrooms, a growing medium (compost) is placed in each of the shelves to a depth of about 12 inches. After all of the shelves in a growing room are filled with the compost, the compost may be compacted or leveled by compressing with a roller. Suitable equipment for such compacting is shown, for example, in U.S. Pat. Nos. 8,561,344; 8,205,379 and 8,069,608.
Thereafter, the entire room is sealed off, and the compost is allowed to heat up thereby completing pasteurization. Or, the grower places pre-pasteurized compost onto the shelves. After pasteurization, the compost is spawned (planted with the seed). Approximately 14 days after spawning, the compost is covered with a layer of soil (casing) to induce fruiting of the mushrooms. While casing can be dumped by bucket and raked onto the compost bed manually, more commonly a material handling apparatus such as shown in U.S. Pat. No. 4,371,305 can be used. The material handling apparatus of the '305 patent has a distributor box that deposits casing material onto a horizontally moving belt from which the casing is discharged onto the prepared bed of mushroom compost at the reversal point of the unwinding belt. Within the distributor box is a rotating auger to break up the soil and direct it downwardly to a gap between the bottom of the front wall of the distributor box and the moving belt. Also within the distributor box is a reciprocating device with a bar from which teeth extend. The bar is oscillated or reciprocated from side to side. The teeth associated with the bar sweep back and forth to dislodge clumps and stones in the casing soil, thereby preventing clogging of the gap between the bottom of the front wall of the distributor box and the moving belt. A cut-off plate is angled into the distributor box in advance of the gap. The contents of U.S. Pat. No. 4,371,305 are incorporated herein by reference.
Mushroom growers have in recent times changed the type of casing that is deposited onto the prepared mushroom compost bed from soil to a peat moss. The peat moss comprises lighter, finely divided particles with a preferred moisture content of from about 80% to 85%. It has been found that material handling apparatus such as that shown in the '305 patent is not effective to lay this type of peat moss casing in a uniform layer onto a prepared bed. Accordingly, improvements to preparing beds for mushroom cultivation continue to be sought.
While certain aspects of prior art methods and apparatus for preparing beds for mushroom cultivation have been discussed, aspects of these systems are in no way disclaimed and it is contemplated that the claimed invention may encompass one or more aspects of the prior art devices discussed herein.